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// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include <string>
#include "base/compiler_specific.h"
#include "base/gtest_prod_util.h"
#include "base/macros.h"
#include "base/memory/scoped_ptr.h"
#include "base/synchronization/lock.h"
#include "base/task_runner.h"
#include "chromeos/chromeos_export.h"
#include "chromeos/login/auth/auth_attempt_state.h"
#include "chromeos/login/auth/auth_attempt_state_resolver.h"
#include "chromeos/login/auth/authenticator.h"
#include "chromeos/login/auth/test_attempt_state.h"
#include "google_apis/gaia/gaia_auth_consumer.h"
class AuthFailure;
namespace content {
class BrowserContext;
namespace chromeos {
class AuthStatusConsumer;
// Authenticates a Chromium OS user against cryptohome.
// Relies on the fact that online authentications has been already performed
// (i.e. using_oauth_ is true).
// At a high, level, here's what happens:
// AuthenticateToLogin() calls a Cryptohome's method to perform offline login.
// Resultes are stored in a AuthAttemptState owned by CryptohomeAuthenticator
// and then call Resolve(). Resolve() will attempt to
// determine which AuthState we're in, based on the info at hand.
// It then triggers further action based on the calculated AuthState; this
// further action might include calling back the passed-in AuthStatusConsumer
// to signal that login succeeded or failed, waiting for more outstanding
// operations to complete, or triggering some more Cryptohome method calls.
// Typical flows
// -------------
// Login as existing user: CONTINUE > OFFLINE_LOGIN
// Login as existing user (failure): CONTINUE > FAILED_MOUNT
// Change password detected:
// Old password failure: NEED_OLD_PW
class CHROMEOS_EXPORT CryptohomeAuthenticator
: public Authenticator,
public AuthAttemptStateResolver {
enum AuthState {
CONTINUE = 0, // State indeterminate; try again with more info.
NO_MOUNT = 1, // Cryptohome doesn't exist yet.
FAILED_MOUNT = 2, // Failed to mount existing cryptohome.
FAILED_REMOVE = 3, // Failed to remove existing cryptohome.
FAILED_TMPFS = 4, // Failed to mount tmpfs for guest user.
FAILED_TPM = 5, // Failed to mount/create cryptohome, TPM error.
CREATE_NEW = 6, // Need to create cryptohome for a new user.
RECOVER_MOUNT = 7, // After RecoverEncryptedData, mount cryptohome.
POSSIBLE_PW_CHANGE = 8, // Offline login failed, user may have changed pw.
NEED_NEW_PW = 9, // Obsolete (ClientLogin): user changed pw,
// we have the old one.
NEED_OLD_PW = 10, // User changed pw, and we have the new one
// (GAIA auth is OK).
HAVE_NEW_PW = 11, // Obsolete (ClientLogin): We have verified new pw,
// time to migrate key.
OFFLINE_LOGIN = 12, // Login succeeded offline.
ONLINE_LOGIN = 13, // Offline and online login succeeded.
UNLOCK = 14, // Screen unlock succeeded.
ONLINE_FAILED = 15, // Obsolete (ClientLogin): Online login disallowed,
// but offline succeeded.
GUEST_LOGIN = 16, // Logged in guest mode.
PUBLIC_ACCOUNT_LOGIN = 17, // Logged into a public account.
SUPERVISED_USER_LOGIN = 18, // Logged in as a supervised user.
LOGIN_FAILED = 19, // Login denied.
OWNER_REQUIRED = 20, // Login is restricted to the owner only.
FAILED_USERNAME_HASH = 21, // Failed GetSanitizedUsername request.
KIOSK_ACCOUNT_LOGIN = 22, // Logged into a kiosk account.
REMOVED_DATA_AFTER_FAILURE = 23, // Successfully removed the user's
// cryptohome after a login failure.
CryptohomeAuthenticator(scoped_refptr<base::TaskRunner> task_runner,
AuthStatusConsumer* consumer);
// Authenticator overrides.
void CompleteLogin(content::BrowserContext* context,
const UserContext& user_context) override;
// Given |user_context|, this method attempts to authenticate to your
// Chrome OS device. As soon as we have successfully mounted the encrypted
// home directory for the user, we will call consumer_->OnAuthSuccess()
// with the username.
// Upon failure to login consumer_->OnAuthFailure() is called
// with an error message.
// Uses |context| when doing URL fetches.
void AuthenticateToLogin(content::BrowserContext* context,
const UserContext& user_context) override;
// Given |user_context|, this method attempts to authenticate to the cached
// user_context. This will never contact the server even if it's online.
// The auth result is sent to AuthStatusConsumer in a same way as
// AuthenticateToLogin does.
void AuthenticateToUnlock(const UserContext& user_context) override;
// Initiates supervised user login.
// Creates cryptohome if missing or mounts existing one and
// notifies consumer on the success/failure.
void LoginAsSupervisedUser(const UserContext& user_context) override;
// Initiates incognito ("browse without signing in") login.
// Mounts tmpfs and notifies consumer on the success/failure.
void LoginOffTheRecord() override;
// Initiates login into a public session.
// Mounts an ephemeral cryptohome and notifies consumer on the
// success/failure.
void LoginAsPublicSession(const UserContext& user_context) override;
// Initiates login into the kiosk mode account identified by |app_user_id|.
// Mounts an ephemeral guest cryptohome if |use_guest_mount| is |true|.
// Otherwise, mounts a public cryptohome, which will be ephemeral if the
// |DeviceEphemeralUsersEnabled| policy is enabled and non-ephemeral
// otherwise.
void LoginAsKioskAccount(const std::string& app_user_id,
bool use_guest_mount) override;
// These methods must be called on the UI thread, as they make DBus calls
// and also call back to the login UI.
void OnAuthSuccess() override;
void OnAuthFailure(const AuthFailure& error) override;
void RecoverEncryptedData(const std::string& old_password) override;
void ResyncEncryptedData() override;
// AuthAttemptStateResolver overrides.
// Attempts to make a decision and call back |consumer_| based on
// the state we have gathered at the time of call. If a decision
// can't be made, defers until the next time this is called.
// When a decision is made, will call back to |consumer_| on the UI thread.
// Must be called on the UI thread.
void Resolve() override;
void OnOffTheRecordAuthSuccess();
void OnPasswordChangeDetected();
~CryptohomeAuthenticator() override;
typedef base::Callback<void(bool is_owner)> IsOwnerCallback;
// Method to be implemented in child. Return |true| if user specified in
// |context| exists on device.
virtual bool IsKnownUser(const UserContext& context) = 0;
// Method to be implemented in child. Return |true| if device is running
// in safe mode.
virtual bool IsSafeMode() = 0;
// Method to be implemented in child. Have to call |callback| with boolean
// parameter that indicates if user in |context| can act as an owner in
// safe mode.
virtual void CheckSafeModeOwnership(const UserContext& context,
const IsOwnerCallback& callback) = 0;
friend class CryptohomeAuthenticatorTest;
// Removes the cryptohome of the user.
void RemoveEncryptedData();
// Returns the AuthState we're in, given the status info we have at
// the time of call.
// Must be called on the IO thread.
AuthState ResolveState();
// Helper for ResolveState().
// Given that some cryptohome operation has failed, determine which of the
// possible failure states we're in.
// Must be called on the IO thread.
AuthState ResolveCryptohomeFailureState();
// Helper for ResolveState().
// Given that some cryptohome operation has succeeded, determine which of
// the possible states we're in.
// Must be called on the IO thread.
AuthState ResolveCryptohomeSuccessState();
// Helper for ResolveState().
// Given that some online auth operation has succeeded, determine which of
// the possible success states we're in.
// Must be called on the IO thread.
AuthState ResolveOnlineSuccessState(AuthState offline_state);
// Used for testing.
void set_attempt_state(TestAttemptState* new_state) { // takes ownership.
// Used for testing to set the expected state of an owner check.
void SetOwnerState(bool owner_check_finished, bool check_result);
// checks if the current mounted home contains the owner case and either
// continues or fails the log-in. Used for policy lost mitigation "safe-mode".
// Returns true if the owner check has been successful or if it is not needed.
bool VerifyOwner();
// Handles completion of the ownership check and continues login.
void OnOwnershipChecked(bool is_owner);
// Signal login completion status for cases when a new user is added via
// an external authentication provider (i.e. GAIA extension).
void ResolveLoginCompletionStatus();
scoped_refptr<base::TaskRunner> task_runner_;
scoped_ptr<AuthAttemptState> current_state_;
bool migrate_attempted_;
bool remove_attempted_;
bool resync_attempted_;
bool ephemeral_mount_attempted_;
bool check_key_attempted_;
// When the user has changed her password, but gives us the old one, we will
// be able to mount her cryptohome, but online authentication will fail.
// This allows us to present the same behavior to the caller, regardless
// of the order in which we receive these results.
bool already_reported_success_;
base::Lock success_lock_; // A lock around |already_reported_success_|.
// Flags signaling whether the owner verification has been done and the result
// of it.
bool owner_is_verified_;
bool user_can_login_;
// Flag indicating to delete the user's cryptohome the login fails.
bool remove_user_data_on_failure_;
// When |remove_user_data_on_failure_| is set, we delay calling
// consumer_->OnAuthFailure() until we removed the user cryptohome.
const AuthFailure* delayed_login_failure_;
} // namespace chromeos